It is known in the art relating to engine oil pumps to vary the pump displacement as a function of pump outlet pressure in order to maintain a constant oil outlet pressure as the speed of the engine driving the pump is varied. This mode of control increases engine efficiency with a positive displacement pump by reducing the volume of oil pumped at higher engine speeds with a resultant saving of energy. However, with the varying demands being made to provide smaller but more powerful engines having increased fuel economy, consideration was given to modifying the pressure oil control system to allow some increase in controlled oil pressure as a function of increased engine speed. A simplified system for providing such an improvement was desired.